On 16.11.22 04:31, Ted Yu wrote: > On Wed, 16 Nov 2022 at 11:15, Ted Yu <yuzhihong@gmail.com > <mailto:yuzhihong@gmail.com>> wrote: > > On Tue, Nov 15, 2022 at 7:12 PM Japin Li <japinli@hotmail.com > <mailto:japinli@hotmail.com>> wrote: > >> After some rethinking, I find the origin code do not have problems. > >> > >> If fd is NULL or fgets() returns NULL, the process exits. > Otherwise, we > >> call > >> pclose() to close fd. The code isn't straightforward, however, > it is > >> correct. > > Hi, > Please take a look at the following: > > https://en.cppreference.com/w/c/io/fgets > <https://en.cppreference.com/w/c/io/fgets> > Quote: If the failure has been caused by some other error, sets the > /error/ indicator (see ferror() > <https://en.cppreference.com/w/c/io/ferror>) on |stream|. The contents > of the array pointed to by |str| are indeterminate (it may not even be > null-terminated).
That has nothing to do with the return value of fgets().
Hi, Peter:
Here is how the return value from pclose() is handled in other places:
+ if (pclose_rc != 0) + {
+ ereport(ERROR,
The above is very easy to understand.
While the check in `adjust_data_dir` is somewhat harder to comprehend.
I think the formation presented in patch v1 aligns with existing checks of the return value from pclose().
It also gives a unique error message in the case that the return value from pclose() indicates an error.
